/nu·clei/ (noo´kle-i) [L.] plural of nucleus.
1 the central controlling body within a living cell, usually a spheric unit enclosed in a membrane and containing genetic codes for maintaining life systems of the organism and for issuing commands for growth and reproduction.
2 a group of nerve cells of the central nervous system having a common function, such as supporting the sense of hearing or smell.
3 the center of an atom consisting of an element-specific number of protons and neutrons. A probability cloud of electrons exists around the atomic nucleus.
4 the central element in an organic chemical compound or class of compounds. Formerly called cytoblast. -nuclear, adj.
For spallation sources, non-fissile nuclei of mass number A > 100 emerge as appropriate targets .
Less electrostatic repulsion occurs during collisions including nuclei that are unstable because they have excess neutrons than during collisions of stable nuclei.
Knowing these temperatures will make it possible to better identify the stages that nuclei pass through as they crumble from an orderly arrangement of nucleons into a disorderly high-energy gas, says Magne Guttormsen, who led the research team.
However, nuclei also contain uncharged neutrons, which can arrange themselves among the protons to make nuclei more durable than would otherwise be expected.
Greenberg suggests that the clumps may protect nuclei from toxic effects of the unbound mutant proteins.
It is difficult to attribute these bands of condensation nuclei to particular planes because the Federal Aviation Administration doesn't keep records long enough to be useful to the researchers, says Hofmann.
We haven't actually measured the deformation, but our results show these nuclei to be highly deformed," says Cary N.
8 CELL, they report that weeks before symptoms strike the mice, spherical deposits appear in the nuclei of some of the animals' brain cells.
While transplantation of early embryonic nuclei proved successful, researchers almost always failed with transfers of older nuclei-those from the cells of a late-stage fetus or an adult.
For reasons still under study, nuclei from these cells are more readily accepted by eggs.
After hearing results of recent experiments observing collisions between nuclei of lead, many were ready to take seriously the notion that such collisions could produce ultramicroscopic fireballs of quark-gluon plasma.
Researchers are now starting to take advantage of a new, highly sensitive instrument for detecting gamma rays emitted by atomic nuclei.